Headley has admitted conducting advance surveillance for the operation in India.

Although Headley, 52, was facing up to life in prison, the Justice Department recommended that the judge sentence him to the term he eventually got after the defendant cooperated with U.S. authorities.

Prosecutors agreed not to seek the death penalty in exchange for his plea on terrorism charges. He signed that agreement in 2010 and promised to cooperate with U.S. authorities.

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Attorney General Eric Holder noted at the time that he had provided extensive "valuable intelligence about terrorist activities."

Name change helped facilitate the surveillance in India

Headley was arrested by federal agents on October 2009 in Chicago, accused of helping plan terror attacks against a Danish newspaper that ran cartoons of the Prophet Mohammed, sparking Muslim anger worldwide.

He was later linked to the bloody four-day terrorist siege in Mumbai. Headley cooperated with the authorities investigating both terror plots.

Headley received a Social Security number in Pennsylvania sometime in the late 1970s, public records show.

He changed his name from Daood Gilani to David Headley on or about February 15, 2006, in Philadelphia in order to present himself in India as an American who was neither Muslim nor Pakistani, according to a criminal complaint against him.

The Justice Department also accused him of attending terrorism training camps in Pakistan in 2002 and 2003, and working with the group Lashkar-e-Tayyiba to carry out terror attacks.

The United States lists Lashkar as a terrorist organization. India blamed the group for the Mumbai attacks.

"While his criminal conduct was deplorable, the uniquely significant cooperation which he provided to the government's efforts to combat terrorism support the government's recommendations," Shapiro said.

The Indian government wants to conduct another trial for Headley, but the United States has said it would not send him to any other country.